Glow plugs only make starting easier for diesels. If you put the vehicle in a warm location and let it sit overnight, it should start even without glow plugs if the engine isn't too cold. Make certain that you are getting fuel to the injector pump assembly. With someone cranking the engine, loosen the fuel inlet at the injector pump and see if you have any fuel pressure to the high-pressure injector pump. If not, check the filter and low pressure pump.
not necessarily unless after replacing plugs your engine misfires.
On older cars it would be replacing, PCV valve, spark plugs, plug wires, rotor, condenser, and possibly distributor cap. On newer cars it usually means replacing plugs & plug wires.
Diesel
Worn spark plugs would cause mis-firing or non firing cylinders, both are no good for the engine, replacing the plugs may stop the knock (Could also be a different problem) But you should replace spark plugs as soon as possible.
Not to tight just snug
No, not unless your connect the plug wires wrong or one of the new spark plugs was bad.
Replace the plugs or toss some bars leak in it. keep in mind however that when the plugs start to leak they nearly always need replacing.
To fix an engine with no compression first try replacing the spark plugs. Remove the spark plug wire and then remove the spark plug. Replace the plug with a new one. Reattach the wire. Replace all of your plugs and see if your engine will fire.
there a lot of things, the main ones are lack of air, and the spark plugs need replacing.
Freeze plugs. More likely that hoses are leaking or thermostat housing is leaking. Freeze Plugs generally NEVER leaks unless engine block has had frozen coolant in it. Hence, Freeze Plugs.
Rebuild the engine. Oil is leaking past the rings. You will likely note that it is blowing blue smoke as well.
This was a design Ford tried on the 4 cylinder engine. The 2 plugs per cylinder was supposed to give you a more complete burn of fuel thus increasing power and mileage. When replacing the plugs, install 8 on this engine.